1. Field of the Invention
The present invention relates to an automatic light regulating power supply device, and in particular to an automatic light regulating power supply device connected directly to a local AC power supply, to control the LED light string for emitting lights of different brightnesses.
2. The Prior Arts
With the increase of standard of living, the living quarters design is essential and is progressing rapidly. In this respect, lighting design is getting more emphasis and attention, to match it with aesthetical appeal of living space to achieve harmony. As such, Light-Emitting-Diode (LED) lighting device has become a mainstay in the market for its various advantages of long service life, power conservation, low failure rate, stable light emission, high illumination efficiency, and compatible with various lighting devices, as compared with the conventional tungsten-filament light bulbs.
An ordinary LED lighting device is composed mainly of a small-sized Light Emitting Device (LED) light tube, and a power supply device, for which light emission is realized through driving the LED light tube with DC power converted from AC power as supplied by the power supply device. In such a design, the LED lighting device has only two modes of operations: a lighting mode and a non-lighting mode depending on whether power is supplied. As such, it is inferior to the conventional tungsten-filament light bulbs in that, that can be regulated to have various degrees of light illuminations depending on the amount of power supplied. Therefore, the conventional LED lighting device is not able to fulfill the requirement of user putting emphases on living quality and energy conservation, that light illumination can be adjusted to create a suitable atmosphere according to the times and occasions as required. In addition, the LED lighting device having only lighting and non-lighting modes tends to cause waste of energy that limits its application, thus it is not practicable and convenient for most of the stores and households putting emphases on creating a good atmosphere to use it for illumination purpose, also it is not able to fulfill the requirement of energy conservation of the modern times.
Moreover, the LED lighting device can only be driven by DC power as its power supply. Presently, ordinary stores and households all utilize AC power supplied by the local power company, so the front end of conventional LED lighting device must be connected to an LED power supply device to perform the power conversion as required, so that not only its application is limited, but its production cost is also increased.
Therefore, presently, the design and performance of LED lighting device is not quite satisfactory, and it has much room for improvements. There is an urgent need to develop a LED power control technology able to solve the above-mentioned problems.